An image forming apparatus such as an electrophotographic color printer of a tandem type includes: photosensitive members corresponding to four colors, i.e., black, yellow, magenta and cyan, respectively; and a conveying belt opposing the photosensitive members.
However, the photosensitive members always contact the conveying belt. Consequently, for example, even when a monochrome image is formed, the remaining photosensitive members not used for an image formation, i.e., of yellow, magenta and cyan may deteriorate.
A color image recording apparatus is proposed as an example of image forming apparatus for preventing such deterioration of the photosensitive member. The color image recording apparatus includes: one color image forming unit containing image forming units of yellow, magenta and cyan; and another unit containing an image forming unit of black. In the color image recording apparatus, when a monochrome image is formed, the color image forming unit is separated from a conveying belt.